Does silicon and irrigation have impact on drought tolerance mechanism of sorghum?

Silicon absorption by crops in the form of silicic acid confers efficient utilization of available irrigation water by minimizing transpiration losses. In present study, silicon and irrigation effects on sorghum growth dynamics and drought tolerance mechanism were evaluated during 2007-2008. Two sorghum cultivars: PARCSS2 and Johar1 were treated with two levels of silicon (Si-0 = control and Si-200 = 200 ml l(-1) of potassium silicate per kg of soil) and irrigation (W-0 = control, crop lower limit and W-40 = 40 mm of water, crop upper limit). The results depicted that silicon absorption led to increased leaf water potential, growth, transpiration, net photosynthetic rate and decreased shoot to root ratio in sorghum cultivars compared to control treatment. It can be concluded that synergistic effect of silicon fertilization with ample irrigation may improve the crop stand under drought and biotic stresses. (C) 2011 Elsevier B.V. All rights reserved.